Tool-holder.



0. H. PIEPBR. TOOL HOLDER. APPLICATION FILED SEPT. z. 1911.

Patented Dec. 8, 1914.

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O. H. PIEPBR. Too'L HOLDER. APPLICATION PILBD SEPT. 2, 1911.

Patented Dec. 8, 1914.

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5513 @M M ZD lmmmp OSCAR H. PIEPER, OF ROCHESTER, NEW YORK.

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Specification of Letters Patent.

Patented Dec. 8, 1914.

Application led September 2, 1911. Serial No. 647,353.

i To all 'whom it may concern:

' State of New York, have invented certain new and useful Improvements in Tool- Holders; and I do hereby declare the followingto be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked thereon.

The present invention relates to improvements in tool holders, being particularly adaptable for use in connection with rotary tools and implements such as grinding wheels and the like, which may be employed in connection with dental and other similar work, and it has for its object to provide a novel mechanism to enable readily securing the tool in operative position, or detaching the same, while the driving mechanism is in operation.

A further object of the invention isto provide means whereby the tool may be instantly released from the driving member without stopping the movement of the latter.

To these and other ends the invention consists in certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a view in elevation, illustrating a drive member having a tool attached, and embodying a preferred form of my invention; Fig. 2 is a longitudinal vertical section of the same, with parts appearing in elevation; Fig. 3 is a transverse sectional view on the line 3-3 of Fig. 2; Fig. 4 is a view in side elevationof the end of the drive member, with the slidable collar removed; Fig. 5 is a longitudinal vertical sectional view of the drive member, showing the gripping devices in re leasing position, and Fig. 6 is a longitudinal vertical sectional view illustrating a modified form of my invention.

Similar reference numerals throughout the several figures indicate the same parts.

In the present embodiment, 1 designates the drive member, lpreferably embracing a sleeve attached to a shaft 2, which is driven of power, as usual in this class of devices. The drive member is provided with suitably formed oppositely and 10, respectively, which disposed openings, ed gripping devices 3, the latter being held outwardly, or in releasing position, by means of coil springs 4 arranged in suitable pockets between the oppositely disposed gripping devices and engaging the latter, as `shown in Fig. 3. The gripping devices are held inwardly, or in engaging position, in a manner that will presently be described, so as to secure the tool to the drive member for rotation, the tools of the present em; bodimentcomprising the grinding wheel 5 which is suitably threaded on the tapered spindle 6, the latter being provided with a threaded shank 7 arranged to be engaged by the gripping devices aforementioned.

The gripping devices are held normally in threaded engagement with the shank 7, being provided with conveniently means for quickly releasing the shank when it is desired to remove the tool from the drive member, and to this end, in the pres'- ent embodiment, there is provided a collar 8, slidably arranged on the drive member, and having a tapered interior surface which engages the gripping devices. The collar is suitably provided with the end plates 9 are secured thereto in any desirable manner, for a purpose that will now be made clear.

The plate 9 is arranged to contact with the shoulder l1 which is formed on the drive member, while the shoulder 12 coperates with the plate 10, to hold in place the spring 13, the latter serving normally, to hold the parts in the position shown in Fig. 2, the tools being thus held by the drive member. Movement of the collar is limited by the band 14, arranged about the spring 13, so as to engage the plate 10, when the latter is moved against the spring. It will be noted that the plates 9 and 10 project slightly beyond the collar 8 so as to afford a seat for a knurled sleeve 15`which is arranged therebetween, being loosely arranged on the collar, so as'to rotate about the same. The collar 8 is held normally in the position shown in Fig. 2 by means of the spring 13, which forces the gripping devices inwardly into threaded engagement with the shank 7, whereby the latter is held tightly engaged in the driving member, and is rotated therewith." The tool Carrying shank may be moved into engagement with the drive member, by merely holding the same within the latter while it is turning, causing the threadoperated which receive the thread.

ed shank to move into engagement with the threaded gripping devices, as usual with this general type of device. When it is desired to release the tool from the drive member, the collar is moved longitudinally to the position shown in Fig. 5, the interior conical surface permitting the gripping devices to move outwardly under the action of the springs 4, so as to release the shank from engagement and permit the same to be removed. The knurled sleeve, already mentioned, is provided to enable the ready operation of the collar in case of undue frictional engagement between the driving member and collar. Freezing of the parts is entirely obviated by this sleeve arrangement of rotating loosely upon the collar. As soon as pressure is removed from the collar, the spring 13 immediately returns to 'normal position, and the parts are in readiness to receive another tool for operation.

Fig. 6 illustrates va modified form of my invention where the slidable collar is held in 4 engagement with the gripping devices frictool from engagement.

tionally and without the use of the spring employed in the form already described. To this end, the collar 16 is provided with a. conical surface 17 and a straight surface 18 which extends parallel with the outer surface of the collar. The shoulder on the drive member is provided with the beveled portion 19 and the gripping devices 20 are correspondingly beveled, as indicated at 21, so as to enable the slidable collar to move readily from its one extreme position to the other, and to permit the gripping devices on the drive member to slide easily from the conical surface of the collar onto the flat surface. The frictienal engagement between the parts is sufficient to hold the straight surface of the collar in engagement with the gripping devices after being positioned. With this form of my invention, the gripping devices are held in engaging position, to lock the tool shank to the drive member, when the parts are in the pbsition shown in Fig. 6. And when it is desired to release the tool, the collar is moved longitudinally site the gripping devices, thereby permitting the latter to move outwardly under the action oftheir springs, and thus to release the v To lock the parts again, the collar must be positively moved back into locking position.

While I have disclosed in the present application certain preferred embodiments of my invention, it will be understood that I do not limit myself to the exact forms of construction herein described and set forth, but

until the conical surface is oppo' intend to cover any other modiications and departures that may come within the terms of the claims hereto appended.

I claim as my invention:

1. In a tool holder, the combination with a drive member adapted to receive the shank of a tool, of gripping devices movable transversely of the drive member, said drive member having recesses for holding the gripping devices, and transversely arranged openings connecting the recesses, springs positioned in said openings having engagement with the gripping devices, a collar surrounding the drive member, said collar having its interior surface tapering throughout and in engagement with the gripping devices, and means for normally holding the innermost portion of said vtapering surface in engagement with the gripping devices.

2. In a tool holder, the combination with a drive member, of threaded spring controlled gripping devices arranged in recesses in the driving member, a shoulder on the drive member, the latter being also provided with transverse openings connecting said recesses, springs arranged in said openings and in engagement with the gripping devices, a collar surrounding the drive member having its interior surface tapered throughout' and in engagement with the grippingdevices, a spring disposed between one end of the collar and said shoulder on the drive member and a sleeve surrounding said spring and engaging the shoulder on the drive member. Y

3. In a tool holder, the combination with a drive member adapted to Vreceive the shank of a tool, of threaded spring-controlled gripping devices movable transversely of the drive member, said drive member having recesses for holding the gripping devices and transverse openings connecting the recesses, springs arranged in said transverse openings and engaging the gripping devices, a

collar surrounding the drive member hav- R. L. FITCH, y H. E. STONEBRAKER. 

